From e0adfe4d459482240d0614990fcb0ea112d48cf4 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Thu, 30 Jan 2020 12:21:37 +0100
Subject: [PATCH] new compile-fail test involving non-reborrowing-cast-to-raw

---
 tests/compile-fail/stacked_borrows/illegal_read8.rs | 13 +++++++++++++
 tests/run-pass/stacked-borrows/stacked-borrows.rs   |  1 -
 2 files changed, 13 insertions(+), 1 deletion(-)
 create mode 100644 tests/compile-fail/stacked_borrows/illegal_read8.rs

diff --git a/tests/compile-fail/stacked_borrows/illegal_read8.rs b/tests/compile-fail/stacked_borrows/illegal_read8.rs
new file mode 100644
index 000000000000..72fca84ba19b
--- /dev/null
+++ b/tests/compile-fail/stacked_borrows/illegal_read8.rs
@@ -0,0 +1,13 @@
+// Make sure that creating a raw ptr next to a shared ref works
+// but the shared ref still gets invalidated when the raw ptr is used for writing.
+
+fn main() { unsafe {
+    use std::mem;
+    let x = &mut 0;
+    let y1: &i32 = mem::transmute(&*x); // launder lifetimes
+    let y2 = x as *mut _;
+    let _val = *y2;
+    let _val = *y1;
+    *y2 += 1;
+    let _fail = *y1; //~ ERROR borrow stack
+} }
diff --git a/tests/run-pass/stacked-borrows/stacked-borrows.rs b/tests/run-pass/stacked-borrows/stacked-borrows.rs
index 208cb7e15e03..824437f4f1bf 100644
--- a/tests/run-pass/stacked-borrows/stacked-borrows.rs
+++ b/tests/run-pass/stacked-borrows/stacked-borrows.rs
@@ -136,7 +136,6 @@ fn shr_and_raw() { unsafe {
     let y2 = x as *mut _;
     let _val = *y1;
     *y2 += 1;
-    // TODO: Once this works, add compile-fail test that tries to read from y1 again.
 } }
 
 fn disjoint_mutable_subborrows() {